[nexxeln]

Why

Since #26304, Open diff in the tool-call inspector opens the patch that the tool call recorded. The Claude adapter never recorded a patch. It stored Claude's raw Edit or Write result, which is JSON with the hunks and the whole original file. So Open diff on a Claude edit shows "Unsupported diff format. Showing raw patch." and that JSON. The bug first shipped in nightly 0.1.4-nightly.20261028.3822. Stable v0.1.3 is not affected.

This qualifies as a small, focused fix for an obvious bug. It is a regression with an exact cause, and the fix makes no behavior or product decision.

What changed

• ClaudeAdapterV2 turns the structuredPatch hunks in Claude's Edit and Write results into a unified patch with jsdiff, as provider-acp already does. A Write that creates a file gets a patch from /dev/null. apps/server adds diff 8.0.3, the version provider-acp uses.
• A result with no hunks, such as an empty new file, stores no patch. The panel then says "No patch available for this selection." instead of showing JSON.
• A result that does not decode keeps its old text, so a failed edit still shows its error.

Scope

• Covers Claude Edit and Write results recorded after this change. The patch shows what Claude reports, and Claude writes leading tabs as two spaces.
• Leaves out edits recorded before this change. They keep the old JSON and still open raw. A follow-up could convert them on read.
• Leaves out results without structuredPatch, such as Claude subagent edits and NotebookEdit.

Tradeoffs

Restoring the checkpoint-diff fallback in the web client would also hide the JSON. The adapter fix gives every client the exact change from the tool call, and it stops storing the whole original file with each edit.

Blast Radius

The change touches only the diffStr that the Claude adapter stores for new Edit and Write items. Other providers, other Claude tools, and items already stored are unchanged.

Verification

• Failing test first. stores the diff panel patch for $case in ClaudeAdapterV2.test.ts has three rows: an Edit, a Write that creates a file, and a Write that creates an empty file. With the adapter change reverted, all three fail and receive Claude's JSON. With the fix, all three pass, and the full file passes (247 tests).
• Real data. I ran 1,737 Claude file edits from a real install through the web's own toolCallDiff and getRenderablePatch. On main, none render as a diff. With the fix, 1,564 do. The other 173 have no structuredPatch and keep their old text. Stored diffStr for these edits drops from 22.3 MB to 10.0 MB.
• vp run check:changed upstream/main passes. I did not check a live client. Before and after screenshots will be added to this PR.

Written by Claude Opus 5.5 in OpenCode.

Approvability

Verdict: Approved at 829bb03

Macroscope's review found this PR approvable — Claude file-edit results are now formatted as unified diffs rather than raw JSON, with existing fallback behavior for unsupported results. The change affects displayed edit output, not file-edit execution or product defaults.

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No actionable comments were generated in the recent review.

Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: main
• File: .coderabbit.config.ts
• Commit: 5211acf
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: f726c74b-6632-4538-9772-87db6818986d

Commits

Reviewing files that changed from the base of the PR and between 5211acf and 829bb03.

Files ignored due to path filters: 1

• pnpm-lock.yaml is excluded by !**/pnpm-lock.yaml

Files selected for processing: 3

• apps/server/package.json
• apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.test.ts
• apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.ts

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Walkthrough

The Claude adapter now formats structured file-edit results as unified diffs for file-change output. Tests cover edits, nonempty file creation, and empty file creation.

Changes: Claude file-change diff formatting

Layer / File(s)	Summary
Add structured result formatting apps/server/package.json, apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.ts	The server adds the diff dependency. The adapter formats structured edit hunks and file creations as unified diffs, and retains fallback formatting for unrecognized results.
Use formatter for file-change output apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.ts, apps/server/src/orchestration-v2/Adapters/ClaudeAdapterV2.test.ts	File-change output uses the new formatter. Tests check edit diffs, nonempty creation diffs, and the absence of a diff for empty-file creation.

Priority: Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk: Minimal · up to 829bb

The change is mergeable after normal checks; no actionable risk is established in the supplied evidence.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title "fix(claude): Open diff shows Claude edits as a diff instead of raw JSON" describes the main change. The changeset makes ClaudeAdapterV2 format structuredPatch hunks from Claude Edit and Wri…
Description check		The description follows the template. It has Why (Problem), What changed (Change), Scope with a justification for the small-fix exemption and a reference to the regression source, Tradeoffs, Blast Rad…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Title check

Explanation

The title "fix(claude): Open diff shows Claude edits as a diff instead of raw JSON" describes the main change. The changeset makes ClaudeAdapterV2 format structuredPatch hunks from Claude Edit and Write results into unified diff text, so Open diff shows a diff instead of raw JSON. The title is specific, uses a conventional commit prefix, and matches the objectives.

Full details: Description check

Explanation

The description follows the template. It has Why (Problem), What changed (Change), Scope with a justification for the small-fix exemption and a reference to the regression source, Tradeoffs, Blast Radius, and Verification. Verification gives specific results: a failing-first test, 247 passing tests, and 1,737 real-data edits with rendering counts. It also states what was not checked (live client, screenshots pending). The description does not link a triaged issue or maintainer approval, but it argues that the change qualifies for the small-fix exemption. The description also says screenshots will be added later, which the template requires for UI changes. The template does not clearly require the screenshot for this change, so the gap is minor.

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